Last year, the European model's four- and five-day forecasts were about 15 miles more accurate than the National Hurricane Center's official track forecast.

So why have the Europeans become so good at hurricane forecasting?

“It's difficult to distinguish one aspect against another, but there are a number of things that we have improved progressively over the past decade,” Thépaut said.

The European model doesn't actually forecast hurricanes. It's a “global model,” meaning it forecasts conditions around the world.

When a new “run” of the model comes out, it forecasts global weather for the next 10 days.

Part of the model's success in predicting the development and movement of large storms is its resolution.

This means the model divides the surface of the planet into a grid of boxes that are about 10 miles by 10 miles.

The Global Forecast System model, with less computer hardware at its disposal, has a resolution of 16 miles.

But it's not just resolution that matters, Thepaut said. Scientists also have gained a deeper understanding of the physics that control large weather systems and have improved their ability to model those conditions.

“In 2007, we made big changes to the model's physics, in particular the convection and clouds,” he said. “This had quite a large impact on our skill with tropical cyclones.''

Thépaut said European scientists also are much better at how they incorporate observations from weather buoys, satellites and other sources into their model.

Richard Pasch, a senior hurricane forecaster at the National Hurricane Center, said the U.S. model is fairly close to the European model in terms of accuracy, but added that improvements are under way.

The GFS model will receive a computer hardware upgrade in 2013 that should put it on roughly equal footing with its European counterpart, Pasch said.

American modelers also are working to improve the way in which data from disparate sources — including buoys, satellites, weather balloons flown by National Weather Service offices and reconnaissance aircraft flying into hurricanes — are incorporated into models to get the best possible forecast.

“It's a real logistical and programming challenge,” Pasch said.

The closer these “initial conditions” are to being correct, the better chance a forecast model has to getting a forecast right.

This is why satellite data is so critical to models, forecasters say, and it's why they're concerned about a looming gap in satellites that fly pole-to-pole orbits.

Outside reviews of U.S. plans to replace the aging polar satellites have characterized it as “dysfunctional.”

There's growing concern about a months-long or even multiyear gap in the availability of such data as the older satellites fail.